Antioxidant response of a common herbivorous fish species (Sarpa salpa): Seasonal variation

Abstract

Within the framework of a biosurveillance of marine species on Tunisian coasts, we studied the salema Sarpa salpa, a fish that is consumed by the people living in this region. There is a seasonal occurrence of hallucinogen effects observed when this fish is consumed by humans. The aim of this work was to determine the seasonal variation in the composition of this fish’s diet and to correlate this variation with the antioxidant activity found in its tissues. The salema that lives around the Island of Kerkennah is primarily a herbivorous fish during all seasons. We observed an increased expression of catalase (CAT) and glutathione peroxidase (GPx) in certain organs compared to the control fish, Diplodus annularis. There was a “season-depending” cumulative effect, appearing in the organs starting with the liver, followed by the brain, and finally the flesh. Moreover, it increases according to the size of the animal and thus to the amount of food it consumes. The hallucinogen effect that the consumption of salema has on humans is parallel to the seasonal variation in the epiphytes that are co-ingested by these fish with their food. A significant correlation (P < 0.01) was also observed between the total toxic dinoflagellates and the antioxidant response: CAT and GPx in liver, brain, and flesh for all seasons and all sizes together.